Hello, I am looking for a developer who would be willing to provide me with the necessary elements to be able to publish the application I created for my brother's company.
Looking for a developer
I doubt this would be allowed, and I doubt any developer would use their own account to publish an app they had no hand in creating. They would be open to various copyright and legal challenges, and they may have their account terminated by Apple.
You should create your own Developer account, pay the fee, and publish the application on that account. Don't involve others.